A data transfer device includes a data buffer, an odd number flag, and a control unit. The data buffer holds an even number of data blocks from a data transfer controller. The odd number flag is set when the number of data blocks to be transferred to a receiving device is odd. The control unit transfers an even number of data blocks to the receiving device for each data transfer cycle with respect to the receiving device, and transfers one data block to the receiving device in a last transfer cycle when the odd number flag is set. Thus, also when the data transfer controller which transfers data in a unit of an even number of data blocks is used, not only an even number of data blocks but an odd number of data blocks may be transferred to the receiving device.